NEW YORK (CBSNewYork/AP) – Tensions were running high in New York City late Thursday, after a pair of unattended gift boxes containing toys sparked a partial evacuation of the Time Warner Center at Columbus Circle.

Officials say the second and third floors of the complex’s mall were evacuated, while the first floor remained open.

The packages were quickly deemed safe, but the response highlighted the anxious mood felt across the city just one day after a pipe bomb was discovered in a parcel delivered to CNN’s New York headquarters, also located in the Time Warner Center. The explosive device found Wednesday morning was one of ten officials say targeted prominent Democrats across the country, as well as the news network, over the past four days.

Authorities held a briefing on the latest in the investigation Thursday afternoon.

“The message today is that New Yorkers are safe,” NYPD Commissioner James O’Neill said, adding there were no further credible threats to any persons or organizations in the city.

Sources tell CBS2 that the package addressed to De Niro was received at TriBeCa Productions on Greenwich Street Thursday morning and brought to a security office. A retired NYPD intelligence bureau detective who works in security in the building reported a package after seeing images of the other package bombs on TV, according to Deputy Commissioner John Miller.

At around 4 a.m., he called the NYPD and told them about what he received and where to find it, prompting the NYPD’s bomb squad to respond. They X-rayed the package and decided to remove it for investigation. It was placed into a bomb disposal truck and driven to an NYPD firing range in the Bronx around 6:30 a.m.

No one was hurt and no buildings were evacuated, but streets in the area were shut down for several hours.

Sources tell CBS2 the devices are not rigged like a traditional package bomb. They had timers and batteries but never went off. Law enforcement officials were still uncertain whether the devices were poorly designed or never intended to cause physical harm. Either way, Commissioner O’Neil said Thursday investigators were treating the devices as if they’re real and dangerous.

Police are investigating a suspicious package sent to Robert De Niro in Tribeca.

Mayor Bill de Blasio thanked the NYPD and Bomb Squad for safely removing the device, and singled out the security guard who reported the suspicious parcel.

“The really quick-witted work of a security guard there at that facility in TriBeCa is to thank for the fact that nothing happened and no harm was done to anyone,” de Blasio said.

“This is clearly an effort to terrorize people politically, to chose people for political purposes and attack them because of their beliefs. That is the kind of thing we have seen before in this city and we reject it, we will not be intimidated by it,” de Blasio said. He praised New Yorkers for continuing to go about their business, but called for continued vigilance.

The mayor urged people to call 1-888-NYC-SAFE if they have information regarding the investigation.

An explosive device was found at CNN’s New York officers at the Time Warner Center on Columbus Circle on Oct. 24, 2018. (credit; CNN)

“The pattern of these packages have been extraordinarily consistent. But that does not mean that if something comes in that looks a little different people shouldn’t take it seriously if it’s suspicious to them,” de Blasio said. “If a package looks suspicious, if there’s any kind of chemical smell, any wiring showing, any indication of something out of the ordinary, don’t open the package.”

Each of the devices have been transported to the FBI’s lab in Quantico, Virginia for testing. In New York, residents and commuters alike were on edge as authorities continued to probe the disturbing pattern.

“I used to live next to Columbus Circle, so this has all been really terrifying. We don’t know where it’s going to be sent next,” Greenwich Village resident Jamie Yang said. “I didn’t know if I should go to work.

“It’s a scary time. Nobody’s safe,” said Massapequa resident Fran Marra. “Another day in New York. We’re used to seeing a lot of things.”

“It’s just really scary. I don’t know, I feel like the political climate has gotten so divisive and when violence happens like this, it’s just unsettling,” said Prospect Heights resident Alex Borowski.

“The question on everyone’s mind of course is ‘How long will this go on?'” de Blasio said. “We have to be ready for any eventuality. It might be hours, it might be days, it might be weeks. The vigilance that we have to show in the meantime has to be consistent.”

“We want New Yorkers to know that we’re taking every precaution. They should come to work. They should feel safe,” Gov. Andrew Cuomo said.

On Wednesday night, Cuomo called in the National Guard and doubled police presence around mass transit hubs as a precaution.

“I’ve been governor of New York for seven years, I’ve faced many terrorism situations, and this works on multiple levels. The first level is to do a full investigation. Let’s find the person or people involved,” he said Thursday morning. “Second, especially in New York, you want to retain a sense of control, you want people to know that you’re acting and you’re acting appropriately and they’re safe. Fear is the intent and we are trying to counter fear, so we’ve deployed National Guard, we doubled the state police, you’ll see more of a police presence in New York.”

Out of an abundance of caution, I am deploying additional National Guard soldiers and directing State law enforcement to double security at vital transportation assets across New York.

The governor also called De Niro a “personal friend,” “very great actor” and “great New Yorker.” The TriBeCa Enterprises building, where de Niro’s production company is based, was back in business late Thursday morning.

FBI investigators are working around the clock to identify the source of the suspicious packages, and say it is extremely helpful that none of the devices detonated, which will help them trace the source.

Investigators say some of the bombs were sent through the U.S. Postal Service, but that no new ones have been found in the mail system since late Thursday morning. U.S. Postal Inspection Service spokesman Philip Bartlett said that postal employees and inspectors were searching mail facilities for packages matching the 10 which contained the devices.

Law enforcement sources tell CBS News that FBI agents are at a postal facility in Opa-locka, Florida, where some of the suspicious packages may have originated. Investigators are scrutinizing camera footage at the self-mailing kiosk machines inside the facility in south Florida. They’re also combing through surveillance video footage at the facility and nearby businesses and canvassing the area.

“All arrows pointing to Florida,” one official told CBS News.

New Yorkers, you never stop. And neither do your police.

As you go about your day, you’ll see an increased NYPD presence throughout the city. Know we're out there keeping you safe.

On Wednesday night, President Donald Trump condemned the apparent act of terror after a suspicious device found at the Time Warner Center and CNN’s New York headquarters was addressed to Brennan, prompting an evacuation of the building.

“We will find those responsible and we will bring them to justice, hopefully very quickly,” Trump said.